A long Chandra observation of Tycho has revealed a pattern of X-ray "stripes" never seen before in a supernova remnant. The stripes are seen in the high-energy X-rays (blue) that also show the blast wave, a shell of extremely energetic electrons. Low-energy X-rays (red) show expanding debris from the supernova explosion. The stripes may provide the first direct evidence that a cosmic event can accelerate particles to energies a hundred times higher than achieved by the most powerful particle accelerator on Earth.